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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#ifndef GPU_PROMISE_HELPERS_H_
#define GPU_PROMISE_HELPERS_H_
#include "mozilla/dom/Promise.h"
// Promise's `MaybeResolve*` & `MaybeReject*` methods call into the JS runtime
// and might execute handlers attached by user code. The user code can contain
// calls to the WebGPU API potentially causing us to re-enter the same function
// that called one of Promise's methods in the first place. Rather than adapting
// our code to cope with situations like this, it seems beneficial not to have
// to deal with reentrancy when reading and debugging code in general.
//
// We therefore defer promise resolution to prevent reentrancy.
//
// The only exception to this is in functions that create, resolve/reject and
// return the promise. This is ok because there was no opportunity for JS user
// code to attach handlers to the promise. The WebGPU specification also
// requires us to settle the promise before returning it in some cases (ex:
// `Buffer::mapAsync`).
namespace mozilla::webgpu::promise {
void MaybeRejectWithTypeError(RefPtr<dom::Promise>&& promise,
nsCString&& aMessage);
void MaybeRejectWithOperationError(RefPtr<dom::Promise>&& promise,
nsCString&& aMessage);
void MaybeRejectWithAbortError(RefPtr<dom::Promise>&& promise,
nsCString&& aMessage);
void MaybeRejectWithNotSupportedError(RefPtr<dom::Promise>&& promise,
nsCString&& aMessage);
void MaybeRejectWithInvalidStateError(RefPtr<dom::Promise>&& promise,
nsCString&& aMessage);
void MaybeRejectWithPipelineError(RefPtr<dom::Promise>&& promise,
RefPtr<PipelineError>&& aError);
void MaybeResolveWithUndefined(RefPtr<dom::Promise>&& promise);
void MaybeResolveWithNull(RefPtr<dom::Promise>&& promise);
template <typename T>
void MaybeResolve(RefPtr<dom::Promise>&& promise, RefPtr<T>&& aArg) {
NS_DispatchToCurrentThread(NewCancelableRunnableMethod<RefPtr<T>>(
"webgpu::PromiseHelpers::MaybeResolve", std::move(promise),
&dom::Promise::MaybeResolve<RefPtr<T>>, std::move(aArg)));
}
} // namespace mozilla::webgpu::promise
#endif // GPU_PROMISE_HELPERS_H_